As to "Did you file the election with your 2020 tax return to "Waive the Carryback" of the NOL?", certainly not consciously and frustrated that TurboTax didn't raise this as an issue in the process of dealing with the loss(es). And, it looks like I should have based on this IRS FAQ on NOL carryback: https://www.irs.gov/newsroom/freque[product key removed][product key removed]backs-of-nols-for-taxpa...
It looks like I can either (a) do a carryback for previous tax years or (b) carry forward the loss if I file the waiver form. Is that right?
